.\"-
.\" Copyright (c) 2010 Edward Tomasz Napierala
.\"
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.Dd May 18, 2015
.Dt GMOUNTVER 8
.Os
.Sh NAME
.Nm gmountver
.Nd "control utility for disk mount verification GEOM class"
.Sh SYNOPSIS
.Nm
.Cm create
.Op Fl v
.Ar prov ...
.Nm
.Cm destroy
.Op Fl fv
.Ar name
.Nm
.Cm list
.Nm
.Cm status
.Op Fl s Ar name
.Nm
.Cm load
.Op Fl v
.Nm
.Cm unload
.Op Fl v
.Sh DESCRIPTION
The
.Nm
utility is used to control the mount verification GEOM class.
When configured, it passes all the I/O requests to the underlying provider.
When the underlying provider disappears - for example because the disk device
got disconnected - it queues all the I/O requests and waits for the provider
to reappear.
When that happens, it attaches to it and sends the queued requests.
.Pp
The first argument to
.Nm
indicates an action to be performed:
.Bl -tag -width ".Cm destroy"
.It Cm create
Enable mount verification for the given provider.
If the operation succeeds, a new GEOM provider will be created using the
given provider's name with a
.Ql .mountver
suffix.
The kernel module
.Pa geom_mountver.ko
will be loaded if it is not loaded already.
.It Cm destroy
Destroy
.Ar name .
.It Cm list
See
.Xr geom 8 .
.It Cm status
See
.Xr geom 8 .
.It Cm load
See
.Xr geom 8 .
.It Cm unload
See
.Xr geom 8 .
.El
.Pp
Additional options:
.Bl -tag -width indent
.It Fl f
Force the removal of the specified mountver device.
.It Fl v
Be more verbose.
.El
.Sh SYSCTL VARIABLES
The following
.Xr sysctl 8
variables can be used to control the behavior of the
.Nm MOUNTVER
GEOM class.
The default value is shown next to each variable.
.Bl -tag -width indent
.It Va kern.geom.mountver.debug : No 0
Debug level of the
.Nm MOUNTVER
GEOM class.
This can be set to a number between 0 and 3 inclusive.
If set to 0 minimal debug information is printed, and if set to 3 the
maximum amount of debug information is printed.
.It Va kern.geom.mountver.check_ident : No 1
This can be set to 0 or 1.
If set to 0,
.Nm
will reattach to the device even if the device reports a different disk ID.
.El
.Sh EXIT STATUS
Exit status is 0 on success, and 1 if the command fails.
.Sh SEE ALSO
.Xr geom 4 ,
.Xr geom 8
.Sh HISTORY
The
.Nm
utility appeared in
.Fx 9.0 .
.Sh AUTHORS
.An Edward Tomasz Napierala Aq Mt trasz@FreeBSD.org
